This problem only started happening recently- I had a rebuilt 700R4 put into my IROC about 2 years ago, and it has been fine for those two years. However, quite recently, it seems to be shifting at higher and higher rpms at full throttle. First, when it was put in, it would shift from 1st to 2nd around 4800 RPM (200 rpm short of the 5k redline on my 305) and from 2nd to 3rd just after yellowline (4500 rpms around). Recently, it has been going from 1st to 2nd at 5100-5200 rpms (I'm guessing...a bit too far beyond redline for my liking...) and from 2nd to 3rd at 5000 exactly. Why is this happening? It also seems to be waiting a little longer than usual to downshift during deceleration (slightly hard deceleration), going down to around 500 rpms sometimes (enough to make my volts drop significantly before they come back up). Is this transmission-related, or is this a sensor somewhere going bad?

Also, from 1st to 2nd it isnt a really "firm" shift....it almost seems like it slightly disengages, then drops rpms to the correct rpm for 2nd gear to engage at that throttle, and then "re-engage"...almost like a manual effect, but not as harsh. Only from 1st to 2nd though....any thoughts?

Thank you, whoever can help me out here.